Photolithography systems/tools are used to print features on a substrate in a variety of manufacturing applications. Typically, in operation, a reticle having patterned features is exposed by an illumination source such as, for example, a laser to form images of the features. An optical system projects images of the features onto the substrate.
Conventional photolithography systems control the amount of illumination light that reaches the substrate, for example, by light beam alignment, homogenizers, mechanical trimming, and/or diffractive elements. These conventional techniques disrupt the quality of light that reaches the substrate.
What is needed is a means for attenuating light in a photolithography system, as well as other optical systems, that does not disturb the quality of light.